Add classes ExplicitTrackSizing and MetaGridTrackSize which will allow
for managing properties like auto-fill and minmax.
In the following CSS example there are 3 classes that will be used:
grid-template-column: repeat(auto-fill, minmax(50px, 1fr) 75px);
ExplicitTrackSizing - will contain the entire value. e.g.
repeat(auto-fill, minmax(50px, 1fr) 75px)
With a flag if it's a repeat, as well as references to the
MetaGridTrackSizes which is the next step down.
MetaGridTrackSize:
Contain the individual grid track sizes. Here there are two:
minmax(50px, 1fr) as well as 75px.
This way can keep track if it's a minmax function or not, and the
references to both GridTrackSizes in the case it is, or in just the one
if it is not.
GridTrackSize:
Is the most basic element, in this case there are three in total; two of
which are held by the first MetaGridTrackSize, and the third is held by
the second MetaGridTrackSize.
Examples: 50px, 1fr and 75px.